Unhappy customer

I have bought a phone Sumsung A11 at Edgars wonderpark on the 27 November 2020 and on the 01 December 2020 when I tried to switch off my phone , it ddnt switch on and I went to the shop to report this and the consultant (Mantwa) assistant me and she tried to switch it on but it did not then she called the supply Vodacom and she booked it for repair and on the same day the other client came and she was returning the phone and complaining of the same problem not switching on (Sumsung) but with her case they gave her money. With me the took it and I kept on calling them to find out how long I should wait until on Monday (07/12/2020)they contacted me and let me know they are still awaiting for the reference number to issue the phone. The consultant by the name of Mantwa at wonderpark I asked her since like this Samsung phones are having problem can I exchange with another phone and she agreed. Today the (10/12/2020) they contacted me to let me know that the was nothing wrong with the phone I must come and collect it. I asked them that since like the Samsung at the shop are having a problem I don not want the sumsung phone anymore I rather exchange with another phone , they told me I cannot because the phone is not having a problem. My decision was I want another phone except sumsung I am even willing to add up on the money that I bought the Samsung and take another phone ,they refused and said I must come to the shop. Can Hello Peter assist me in this because I do not want to have the same problem again with the phone. Your help will be highly appreciated, Regards, Ouma ***